RF Power Recovery Unit for Wireless Energy Transfer
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Solution Overview
Problem
Conventional wireless power transfer methods face inefficiencies as power diminishes significantly with increased distance between the source and the charging device, limiting the effectiveness of magnetic inductive coils used in close proximity.
Innovation Solution
A recovery unit is designed to receive radio frequency (RF) power and convert it to direct current (DC) power using antennas, RF-to-DC converters, impedance matching circuits, and programmable loads, with digital control blocks and transceivers to optimize power transfer and communication, allowing for efficient power conversion and dynamic adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If magnetic inductive coils are placed in close proximity for wireless power transfer, then power transfer efficiency is improved, but the distance between source and charging device is limited
Solution Approach 1:
The patent changes the operating parameters by using RF frequency range (e.g., 2.4 GHz WiFi band) instead of traditional magnetic induction frequencies, enabling wireless power transfer over extended distances while maintaining reasonable efficiency through impedance matching circuits and optimized antenna designs
Solution Approach 2:
The patent replaces the magnetic inductive coupling mechanism with RF electromagnetic wave transmission, substituting the near-field magnetic coupling system with a far-field or mid-field RF radiation system that can operate over greater distances without requiring tight physical proximity between coils
2Loss of energy
If coil size is reduced to match wavelength for improved efficiency, then power transfer efficiency increases, but the effective transmission distance decreases
Solution Approach 1:
The patent transitions from the near-field magnetic coupling dimension to the far-field RF radiation dimension, utilizing electromagnetic wave propagation characteristics that allow energy to travel through space over longer distances while maintaining efficiency through proper antenna impedance matching and RF circuit design
3Length of moving object
If RF power is used for wireless power transfer over greater distances, then transmission distance is improved, but power conversion efficiency becomes more challenging
Solution Approach 1:
The patent introduces impedance matching circuits as intermediary components between the RF receiver antenna and the rectifier diode, and between the rectifier output and the load, to maximize power transfer efficiency by eliminating impedance mismatches that would otherwise cause reflected power and energy loss during RF-to-DC conversion
Solution Approach 2:
The patent employs Schottky rectifier diodes and voltage multipliers to replace inefficient linear rectification methods, enabling high-frequency RF signal rectification with minimal power loss and achieving effective RF-to-DC conversion over extended transmission distances
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enhances wireless power transfer efficiency by maintaining effective power delivery over greater distances and optimizing power distribution, ensuring reliable charging of devices while adapting to changing conditions such as interference from objects or living organisms.
Implementation Method 1
at least one antenna for receiving the RF power
Implementation Method 2
an RF-to-DC converter adapted to generate the DC power
Data Source
AI summary
A method of generating a DC power from incident RF waves, includes, in part, measuring the amount of power being received by a device generating the DC power, and controlling the phases of the RF waves being transmitted by a multitude of RF transmitters in accordance with the measured power. A programmable test load is optionally used at the device to measure the received power. The device optionally includes, an antenna, an RF-to-DC converter to generate the DC power, an impedance matching/transformation circuit, and an RF load/matching circuit.